Add missing STJ xml docs

src/libraries/System.Memory.Data/src/System/BinaryDataConverter.cs

@@ -8,6 +8,12 @@ namespace System.Text.Json.Serialization
     /// </summary>
     public sealed class BinaryDataJsonConverter : JsonConverter<BinaryData>
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BinaryDataJsonConverter"/>.
+        /// </summary>
+        public BinaryDataJsonConverter()
+        { }
+
         /// <inheritdoc/>
         public override BinaryData? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
         {

src/libraries/System.Text.Json/src/System/Text/Json/Nodes/JsonArray.cs

@@ -113,9 +113,10 @@ internal int GetElementIndex(JsonNode? node)
         }
 
         /// <summary>
-        /// Returns enumerator that wraps calls to <see cref="JsonNode.GetValue{T}"/>.
+        /// Returns an enumerable that wraps calls to <see cref="JsonNode.GetValue{T}"/>.
         /// </summary>
         /// <typeparam name="T">The type of the value to obtain from the <see cref="JsonValue"/>.</typeparam>
+        /// <returns>An enumerable iterating over values of the array.</returns>
         public IEnumerable<T> GetValues<T>()
         {
             foreach (JsonNode? item in List)

src/libraries/System.Text.Json/src/System/Text/Json/Nodes/JsonNode.cs

@@ -242,6 +242,7 @@ public JsonNode? this[string propertyName]
         /// <summary>
         /// Creates a new instance of the <see cref="JsonNode"/>. All children nodes are recursively cloned.
         /// </summary>
+        /// <returns>A new cloned instance of the current node.</returns>
         public JsonNode DeepClone() => DeepCloneCore();
 
         internal abstract JsonNode DeepCloneCore();

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Attributes/JsonObjectCreationHandlingAttribute.cs

@@ -39,6 +39,7 @@ public sealed class JsonObjectCreationHandlingAttribute : JsonAttribute
     /// <summary>
     /// Initializes a new instance of <see cref="JsonObjectCreationHandlingAttribute"/>.
     /// </summary>
+    /// <param name="handling">The handling to apply to the current member.</param>
     public JsonObjectCreationHandlingAttribute(JsonObjectCreationHandling handling)
     {
         if (!JsonSerializer.IsValidCreationHandlingValue(handling))

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Attributes/JsonUnmappedMemberHandlingAttribute.cs

@@ -14,6 +14,7 @@ public class JsonUnmappedMemberHandlingAttribute : JsonAttribute
         /// <summary>
         /// Initializes a new instance of <see cref="JsonUnmappedMemberHandlingAttribute"/>.
         /// </summary>
+        /// <param name="unmappedMemberHandling">The handling to apply to the current member.</param>
         public JsonUnmappedMemberHandlingAttribute(JsonUnmappedMemberHandling unmappedMemberHandling)
         {
             UnmappedMemberHandling = unmappedMemberHandling;

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonConverterFactory.cs

@@ -142,6 +142,7 @@ internal sealed override void WriteAsPropertyNameAsObject(Utf8JsonWriter writer,
             throw new InvalidOperationException();
         }
 
+        /// <inheritdoc/>
         public sealed override Type? Type => null;
 
         internal sealed override void WriteAsPropertyNameCoreAsObject(

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonConverterOfT.cs

@@ -498,6 +498,7 @@ internal bool TryWriteDataExtensionProperty(Utf8JsonWriter writer, T value, Json
             return success;
         }
 
+        /// <inheritdoc/>
         public sealed override Type Type { get; } = typeof(T);
 
         internal void VerifyRead(JsonTokenType tokenType, int depth, long bytesConsumed, bool isValueConverter, ref Utf8JsonReader reader)

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonNumberEnumConverter.cs

@@ -17,6 +17,11 @@ namespace System.Text.Json.Serialization
     public sealed class JsonNumberEnumConverter<TEnum> : JsonConverterFactory
         where TEnum : struct, Enum
     {
+        /// <summary>
+        /// Initializes a new instance of <see cref="JsonNumberEnumConverter{TEnum}"/>.
+        /// </summary>
+        public JsonNumberEnumConverter() { }
+
         /// <inheritdoc />
         public override bool CanConvert(Type typeToConvert) => typeToConvert == typeof(TEnum);
 

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonSerializer.Read.Document.cs

@@ -113,6 +113,7 @@ public static partial class JsonSerializer
         /// </summary>
         /// <param name="document">The <see cref="JsonDocument"/> to convert.</param>
         /// <param name="jsonTypeInfo">Metadata about the type to convert.</param>
+        /// <returns>A <paramref name="jsonTypeInfo"/> representation of the JSON value.</returns>
         /// <exception cref="System.ArgumentNullException">
         /// <paramref name="document"/> is <see langword="null"/>.
         ///